diff options
Diffstat (limited to 'drivers/misc/enclosure.c')
-rw-r--r-- | drivers/misc/enclosure.c | 69 |
1 files changed, 49 insertions, 20 deletions
diff --git a/drivers/misc/enclosure.c b/drivers/misc/enclosure.c index 348443bdb23b..7b039306037f 100644 --- a/drivers/misc/enclosure.c +++ b/drivers/misc/enclosure.c @@ -33,24 +33,44 @@ static DEFINE_MUTEX(container_list_lock); static struct class enclosure_class; /** - * enclosure_find - find an enclosure given a device - * @dev: the device to find for + * enclosure_find - find an enclosure given a parent device + * @dev: the parent to match against + * @start: Optional enclosure device to start from (NULL if none) * - * Looks through the list of registered enclosures to see - * if it can find a match for a device. Returns NULL if no - * enclosure is found. Obtains a reference to the enclosure class - * device which must be released with device_put(). + * Looks through the list of registered enclosures to find all those + * with @dev as a parent. Returns NULL if no enclosure is + * found. @start can be used as a starting point to obtain multiple + * enclosures per parent (should begin with NULL and then be set to + * each returned enclosure device). Obtains a reference to the + * enclosure class device which must be released with device_put(). + * If @start is not NULL, a reference must be taken on it which is + * released before returning (this allows a loop through all + * enclosures to exit with only the reference on the enclosure of + * interest held). Note that the @dev may correspond to the actual + * device housing the enclosure, in which case no iteration via @start + * is required. */ -struct enclosure_device *enclosure_find(struct device *dev) +struct enclosure_device *enclosure_find(struct device *dev, + struct enclosure_device *start) { struct enclosure_device *edev; mutex_lock(&container_list_lock); - list_for_each_entry(edev, &container_list, node) { - if (edev->edev.parent == dev) { - get_device(&edev->edev); - mutex_unlock(&container_list_lock); - return edev; + edev = list_prepare_entry(start, &container_list, node); + if (start) + put_device(&start->edev); + + list_for_each_entry_continue(edev, &container_list, node) { + struct device *parent = edev->edev.parent; + /* parent might not be immediate, so iterate up to + * the root of the tree if necessary */ + while (parent) { + if (parent == dev) { + get_device(&edev->edev); + mutex_unlock(&container_list_lock); + return edev; + } + parent = parent->parent; } } mutex_unlock(&container_list_lock); @@ -295,6 +315,9 @@ int enclosure_add_device(struct enclosure_device *edev, int component, cdev = &edev->component[component]; + if (cdev->dev == dev) + return -EEXIST; + if (cdev->dev) enclosure_remove_links(cdev); @@ -312,19 +335,25 @@ EXPORT_SYMBOL_GPL(enclosure_add_device); * Returns zero on success or an error. * */ -int enclosure_remove_device(struct enclosure_device *edev, int component) +int enclosure_remove_device(struct enclosure_device *edev, struct device *dev) { struct enclosure_component *cdev; + int i; - if (!edev || component >= edev->components) + if (!edev || !dev) return -EINVAL; - cdev = &edev->component[component]; - - device_del(&cdev->cdev); - put_device(cdev->dev); - cdev->dev = NULL; - return device_add(&cdev->cdev); + for (i = 0; i < edev->components; i++) { + cdev = &edev->component[i]; + if (cdev->dev == dev) { + enclosure_remove_links(cdev); + device_del(&cdev->cdev); + put_device(dev); + cdev->dev = NULL; + return device_add(&cdev->cdev); + } + } + return -ENODEV; } EXPORT_SYMBOL_GPL(enclosure_remove_device); |